1 #ifndef __LINUX_TEXTSEARCH_H 2 #define __LINUX_TEXTSEARCH_H 3 4 #include <linux/types.h> 5 #include <linux/list.h> 6 #include <linux/kernel.h> 7 #include <linux/module.h> 8 #include <linux/err.h> 9 #include <linux/slab.h> 10 11 struct ts_config; 12 13 #define TS_AUTOLOAD 1 /* Automatically load textsearch modules when needed */ 14 #define TS_IGNORECASE 2 /* Searches string case insensitively */ 15 16 /** 17 * struct ts_state - search state 18 * @offset: offset for next match 19 * @cb: control buffer, for persistent variables of get_next_block() 20 */ 21 struct ts_state 22 { 23 unsigned int offset; 24 char cb[40]; 25 }; 26 27 /** 28 * struct ts_ops - search module operations 29 * @name: name of search algorithm 30 * @init: initialization function to prepare a search 31 * @find: find the next occurrence of the pattern 32 * @destroy: destroy algorithm specific parts of a search configuration 33 * @get_pattern: return head of pattern 34 * @get_pattern_len: return length of pattern 35 * @owner: module reference to algorithm 36 */ 37 struct ts_ops 38 { 39 const char *name; 40 struct ts_config * (*init)(const void *, unsigned int, gfp_t, int); 41 unsigned int (*find)(struct ts_config *, 42 struct ts_state *); 43 void (*destroy)(struct ts_config *); 44 void * (*get_pattern)(struct ts_config *); 45 unsigned int (*get_pattern_len)(struct ts_config *); 46 struct module *owner; 47 struct list_head list; 48 }; 49 50 /** 51 * struct ts_config - search configuration 52 * @ops: operations of chosen algorithm 53 * @flags: flags 54 * @get_next_block: callback to fetch the next block to search in 55 * @finish: callback to finalize a search 56 */ 57 struct ts_config 58 { 59 struct ts_ops *ops; 60 int flags; 61 62 /** 63 * get_next_block - fetch next block of data 64 * @consumed: number of bytes consumed by the caller 65 * @dst: destination buffer 66 * @conf: search configuration 67 * @state: search state 68 * 69 * Called repeatedly until 0 is returned. Must assign the 70 * head of the next block of data to &*dst and return the length 71 * of the block or 0 if at the end. consumed == 0 indicates 72 * a new search. May store/read persistent values in state->cb. 73 */ 74 unsigned int (*get_next_block)(unsigned int consumed, 75 const u8 **dst, 76 struct ts_config *conf, 77 struct ts_state *state); 78 79 /** 80 * finish - finalize/clean a series of get_next_block() calls 81 * @conf: search configuration 82 * @state: search state 83 * 84 * Called after the last use of get_next_block(), may be used 85 * to cleanup any leftovers. 86 */ 87 void (*finish)(struct ts_config *conf, 88 struct ts_state *state); 89 }; 90 91 /** 92 * textsearch_next - continue searching for a pattern 93 * @conf: search configuration 94 * @state: search state 95 * 96 * Continues a search looking for more occurrences of the pattern. 97 * textsearch_find() must be called to find the first occurrence 98 * in order to reset the state. 99 * 100 * Returns the position of the next occurrence of the pattern or 101 * UINT_MAX if not match was found. 102 */ 103 static inline unsigned int textsearch_next(struct ts_config *conf, 104 struct ts_state *state) 105 { 106 unsigned int ret = conf->ops->find(conf, state); 107 108 if (conf->finish) 109 conf->finish(conf, state); 110 111 return ret; 112 } 113 114 /** 115 * textsearch_find - start searching for a pattern 116 * @conf: search configuration 117 * @state: search state 118 * 119 * Returns the position of first occurrence of the pattern or 120 * UINT_MAX if no match was found. 121 */ 122 static inline unsigned int textsearch_find(struct ts_config *conf, 123 struct ts_state *state) 124 { 125 state->offset = 0; 126 return textsearch_next(conf, state); 127 } 128 129 /** 130 * textsearch_get_pattern - return head of the pattern 131 * @conf: search configuration 132 */ 133 static inline void *textsearch_get_pattern(struct ts_config *conf) 134 { 135 return conf->ops->get_pattern(conf); 136 } 137 138 /** 139 * textsearch_get_pattern_len - return length of the pattern 140 * @conf: search configuration 141 */ 142 static inline unsigned int textsearch_get_pattern_len(struct ts_config *conf) 143 { 144 return conf->ops->get_pattern_len(conf); 145 } 146 147 extern int textsearch_register(struct ts_ops *); 148 extern int textsearch_unregister(struct ts_ops *); 149 extern struct ts_config *textsearch_prepare(const char *, const void *, 150 unsigned int, gfp_t, int); 151 extern void textsearch_destroy(struct ts_config *conf); 152 extern unsigned int textsearch_find_continuous(struct ts_config *, 153 struct ts_state *, 154 const void *, unsigned int); 155 156 157 #define TS_PRIV_ALIGNTO 8 158 #define TS_PRIV_ALIGN(len) (((len) + TS_PRIV_ALIGNTO-1) & ~(TS_PRIV_ALIGNTO-1)) 159 160 static inline struct ts_config *alloc_ts_config(size_t payload, 161 gfp_t gfp_mask) 162 { 163 struct ts_config *conf; 164 165 conf = kzalloc(TS_PRIV_ALIGN(sizeof(*conf)) + payload, gfp_mask); 166 if (conf == NULL) 167 return ERR_PTR(-ENOMEM); 168 169 return conf; 170 } 171 172 static inline void *ts_config_priv(struct ts_config *conf) 173 { 174 return ((u8 *) conf + TS_PRIV_ALIGN(sizeof(struct ts_config))); 175 } 176 177 #endif 178